The United States has garnered broad support to impose the deadline on Tehran after some intense behind-the-scenes lobbying ahead of Friday's vote at the Vienna-based International Atomic Energy Agency (IAEA).

A western diplomat said the US-led alliance had won support from 25 of the 35-member board to urge Iran to suspend its uranium enrichment program and reveal whether it is enriching uranium to weapons-grade level by the end of October.

The United States has had firm support from key allies France and Germany, which had disagreed sharply with Washington in the showdown over Iraq's alleged arms violations which ultimately led to the war to oust Saddam Hussein.

IAEA chief Mohamed ElBaradei has said at stake was a possible declaration by the body that Iran was in non-compliance with the nuclear Non-Proliferation Treaty (NPT).

If Iran had not provided the requested information by the deadline, ElBaradei might have to tell the board he was "not able to verify non-diversion" of nuclear material from peaceful uses, diplomats said.

The words "non-diversion" were also used in February when North Korea was declared by the IAEA to have breached international safeguard agreements and the matter was referred to the Security Council.

Iran on Friday called on the IAEA governors to resist US pressure to set a deadline, the official Iranian news agency Irna reported.

"We hope the board of governors of the International Atomic Energy Agency will not give in to political pressures," it reported Foreign Minister Kamal Kharazi as saying on his return from a trip abroad.

"The United States and certain western countries are trying to steer the decision by the board of governors towards political objectives," he added.

Washington has been pushing for the broadest support in the vote, which was due later Friday concerned that a "divided board will send a signal to Iran not to take the IAEA too seriously. So they want a broad mandate," a western diplomat said here.

Another diplomat said it was uncertain how the vote on the three-page resolution would take place because Iran could demand that the board votes paragraph by paragraph.

If the members voted in this fashion, it could "expose fissures" in the carefully-crafted support assembled by the United States, he said.

"It may break the coalition," the diplomat said.

The compromise text, submitted by Canada, Australia and Japan, remains tough, saying it is "essential and urgent" for Iran to "remedy all failures" in compliance reported by the IAEA since inspections began in February, after Iran was revealed to more nuclear facilities than thought.

But the language of the resolution has been toned down, "requesting" rather than "calling" for Iran to sign an additional protocol to the NPT to allow IAEA inspectors to make surprise visits to suspect sites.

Cuba and Iran are all but certain to vote against the resolution, and Russia and China are expected to abstain.

But South Africa supports the resolution, a step the United States hopes will lead non-aligned countries to sign on, diplomats said.

Russia is still showing some support by abstaining from the vote even though it feels, as a source at the Russian atomic energy ministry said in Moscow, that Iran must "be given room to maneuver so they are not pushed into a corner like North Korea and withdraw from the NPT."

A diplomat said Russia did not want "to lose Iran as a customer" in its 800 million dollar (734 million euro) deal to build Iran's first nuclear reactor.

WAR.WIRE